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- The effect of seasoning with herbs on the nutritional, safety and sensory properties of reduced-sodium fermented Cobrançosa cv. table olivesPublication . Pires-Cabral, Paula; Barros, Tânia; Mateus, Tânia; Prata, Jessica; Quintas, CéliaThis study aimed at evaluating the effectiveness of seasoning Cobrancosa table olives in a brine with aromatic ingredients, in order to mask the bitter taste given by KCl when added to reduced-sodium fermentation brines. Olives were fermented in two different salt combinations: Brine A, containing 8% NaCl and, Brine B, a reduced-sodium brine, containing 4% NaCl + 4% KCl. After the fermentation the olives were immersed in seasoning brines with NaCl (2%) and the aromatic herbs (thyme, oregano and calamintha), garlic and lemon. At the end of the fermentation and two weeks after seasoning, the physicochemical, nutritional, organoleptic, and microbiological parameters, were determined. The olives fermented in the reduced-sodium brines had half the sodium concentration, higher potassium and calcium content, a lower caloric level, but were considered, by a sensorial panel, more bitter than olives fermented in NaCl brine. Seasoned table olives, previously fermented in Brine A and Brine B, had no significant differences in the amounts of protein (1.23% or 1.11%), carbohydrates (1.0% or 0.66%), fat (20.0% or 20.5%) and dietary fiber (3.4% or 3.6%). Regarding mineral contents, the sodium-reduced fermented olives, presented one third of sodium, seven times more potassium and three times more calcium than the traditional olives fermented in 8% NaCl. Additionally, according to the panelists' evaluation, seasoning the olives fermented in 4% NaCl + 4% KCl, resulted in a decrease in bitterness and an improvement in the overall evaluation and flavor. Escherichia coli and Salmonella were not found in the olives produced.
- The effect of UV-C and electrolyzed water on yeasts on fresh-cut apple at 4 degrees CPublication . Graça, Ana; Santo, David; Pires-Cabral, Paula; Quintas, CéliaThe growth of a yeast mixture, Candida sake, Hanseniaspora uvarum, Pichia fermentans, Metschnikowia pulcherrima, on fresh-cut apple (Royal gala), at 4 degrees C, was studied, as well as the reduction of yeasts using Ultraviolet-C (UV-C), acidic (AEW) and neutral (NEW) electrolyzed waters, and sodium hypochlorite (SH). Apple portions were contaminated then disinfected with UV-C (2.5-10 kJ/m(2)), AEW, NEW and SH (100 ppm). During 9 days at 4 degrees C, yeasts growth rate was 0.34 day(-1) and the stationary phase occurred after 6 days (7.42 LogCFU/g). The initial microbial reduction and the half-life time values, using the inverse hyperbola model, ranged from 1.72 to 1.81 LogCFU/g and 6.52-11.70 day (UV-C), or 0.91 to 1.96 LogCFU/g and 0.68-4.38 day (chemical treatments), where SH was the least efficient (0.92 LogCFU/g and 2.96 day). The most effective treatment was UV-C (7.5 and 10 kJ/m(2)). The yeasts psychrotrophic profile highlights the importance of avoiding contamination/cross-contaminations in all processing.
- Production of split table olives of the Cobrancosa cultivar: a kinetic study of the fermentation profilePublication . PRATA, JESSICA; Barros, Tânia; Mateus, Tânia; Quintas, Célia; Pires-Cabral, PaulaThe aim of this study was to evaluate the effect of the Cobrancosa cultivar olive ripeness on the physicochemical parameters and model their progression profile throughout the fermentation period. Green and turning color olives undertook fermentation due to fruit and environmental microbiota resulting in final brines with the required acidity values and absence of coliforms, Escherichia coli, Salmonella and Listeria monocytogenes. The Monod model was used to explain the changes of a(W), total acidity and total phenolic content in the brines, and the same kinetic with inhibition was fitted to the changes of reducing sugar concentration in the brines. The inverse power model was adjusted to salt content in brines, a(W), total acidity, reducing sugars and total phenolic content in the olives. The Naperian logarithmic function was fitted to the changes of the surface color parameter (-a/b) of the fruits. For both olives, the models adjusted to the experimental data were the same, showing a similar trend in the physicochemical profiles, probably due to the previously fruit splitting, which promotes nutrients diffusing into the brines and the influx of salt into the olives during fermentation. However, different model parameters were estimated, depending on the ripeness degree, namely for total acidity, reducing sugars and total phenolic content of the brines, showing lower nutrients diffusion rates from the unripe olive pulp, through the skin into the brine, due to the hardness of the cell wall structures in this maturation stage.
- Incorporation of capric acid in pumpkin seed oil by sn-1,3 regioselective lipase-catalyzed acidolysisPublication . Sousa, Vanessa; Campos, Vitor; Nunes, Patricia; Pires-Cabral, PaulaStructured lipids (SLs) are novel triacylglycerols obtained by changing the native fatty acid (FA) profiles or by the incorporation of a new desired FA in the acylglycerol backbone. These modified fats present important medical and functional properties for food applications. This work aimed to synthetize a MLM-type SL, which consists of triacylglycerols containing a medium-chain FA (M) at sn-1,3 positions and a long-chain FA (L) at sn-2 position, by acidolysis of pumpkin seed oil with capric acid, catalyzed by a commercial lipase preparation from Thermomyces lanuginosa (Lipozyme TL IM). Reactions were performed at 45 degrees C, in solvent-free media, at 1: 2 molar ratio (pumpkin seed oil: capric acid) and a fixed amount of immobilized lipase of 5%, 10%, 15% or 20%. Incorporations of C10: 0 increased with time up to 31 h (29.9 +/- 0.7 mol-%) when 5% lipase load was used. Significant differences were only observed between the results obtained with 5 and 20% of biocatalyst load. The subsequent experiment was carried out with 5% lipase load, at 45 degrees C, 1: 2 molar ratio and in the presence of n-hexane. The results showed slightly higher incorporation yields in the presence of solvent, namely at 48 h-reaction (34.7 +/- 1.0 mol-%). However, since the structured lipids are to be used in food products, together with environmental and economic concerns, solvent-free systems are preferred. In this study, the synthesis of a MLM-type SL from pumpkin seed oil for food uses was well succeeded.
- Salicornia ramosissima as a salt substitute in the fermentation of white cabbagePublication . Pires-Cabral, Patricia; Pires-Cabral, Paula; Quintas, CéliaThis research aimed to study the fermentation of white cabbage (Brassica oleracea) replacing salt, totally or partially, with halophyte Salicornia ramosissima, to reduce the sodium content in the final products. Three fermentation trials of cabbage were done: A with 2.91% salt (similar to 1.15% Na) (control); B with salicornia (similar to 1.56% salt equivalent, similar to 0.34% Na); and C with salt and salicornia (similar to 1.94% salt equivalent, similar to 0.49% Na). The fermentation profile was followed by the physicochemical (pH, total acidity) and microbial parameters [mesophilic microorganisms (MM), lactic-acid bacteria (LAB), coliforms and fungi]. The content of phenolics and antioxidant activity in the fermented products were also measured. In all experiments, there was an increase, followed by a stabilization of the MM (5.5-7.2 Log CFU/g) and LAB populations (5.4-6.6 Log CFU/g) and a decrease of fungi and coliforms until they disappeared. A decrease in pH (< 4) and a rise in acidity (similar to 1.0%) were observed throughout the fermentations. The phenolics and antioxidant activity increased during fermentation, being significantly higher in C (37.3 mg/100 g and 3.63 mmol Trolox/100 g, respectively). The fermentation of cabbage with salicornia results in the final products having similar microbial quality to the control, but with a reduction of sodium and an increase in the antioxidant activity.
- Effect of chloride salts on the sensory and nutritional properties of cracked table olives of the Macanilha Algarvia cultivarPublication . Saúde, Cíntia; Barros, Tânia; Mateus, Tania; Quintas, Célia; Pires-Cabral, PaulaThe effect of sodium chloride replacement with potassium chloride and/or calcium chloride in the fermentation brines on the physicochemical, organoleptic and nutritional profiles of cracked table olives was studied using no more than 8% salt. Although all brines led to vigorous fermentation with the desired characteristics of acidity and saltiness, the sensory panel rated the olives fermented in 8%NaCl and 4%NaCl + 4%KCl as the best, in terms of flavor and overall attributes. The olives fermented in the other brines (4%NaCl + 4%CaCl2, 4%KCl + 4%CaCl2 and 2.7%NaCl + 2.7%KCl + 2.7%CaCl2) were not acceptable. Olives fermented in 4%NaCl + 4%KCl had lower fat, carbohydrates, dietary fiber, calories and similar amounts of phenolic compounds and Ca as the 8%NaCl treatment. In addition, the former had increased K (672%) and reduced Na (19%), making them more nutritionally acceptable. This alteration might be beneficial and allow the olive market to reach new customers or present current customers with a potentially healthier product.
- The effect of calcium in the fermentation of white cabbage with salicorniaPublication . Pires-Cabral, Patrícia; Pires-Cabral, Paula; Mira, Helena; Quintas, CéliaThis study investigates the fermentation of white cabbage with salicornia and CaCl2 to assess its effect on the fermentation profiles and properties of the final products. Two sets of experiments were performed: A-cabbage with salt and salicornia, and B-cabbage with salt, salicornia, and CaCl2. The fermentative processes were studied through the microbial (lactic-acid bacteria (LAB), coliforms, and fungi), physicochemical (pH, total acidity), and mineral properties. A diminution of pH values (4.07, 3.58) and increased acidity values (0.70, 0.77 g lactic acid/100 mL) were registered at the end of the fermentation period (A and B, respectively). A stationary phase followed the exponential growth of LAB, and a slight decrease was observed (6.01, 5.51 Log CFU/g) in both experiments. A fungi decline was observed during the first week and the coliform populations disappeared after about 13 days of fermentation. Staphylococcus coagulase-positive, Escherichia coli, and Salmonella were not detected in the final products. The utilization of CaCl2 resulted in fermented cabbage with analogous microbial and sensorial characteristics to fermented cabbage without CaCl2 but with an increased hardness. However, Ca interfered with the diffusion of K, Mg, and Zn, resulting in lower levels of these elements in the final product, particularly Zn, which exhibited a reduction of 37%, reducing the nutritional value of the final products.